Add an event listener for chart click events

[uhafner]

Zoomable trend charts should have the same feature set as trend charts in the job page.

[codecov]

Codecov Report

Merging #146 (653d6ae) into master (4d0f861) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #146   +/-   ##
=========================================
  Coverage     64.28%   64.28%           
  Complexity        5        5           
=========================================
  Files             3        3           
  Lines            42       42           
  Branches          3        3           
=========================================
  Hits             27       27           
  Misses           15       15           

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